Friday, April 24, 2026

The Corruption of Power

I read The Man Who Was Thursday recently.  I'm still not sure what I think of its answer to the question of theodicy, but there was a bit that seemed ACKS-relevant:

The poor have sometimes objected to being governed badly; the rich have always objected to being governed at all. Aristocrats were always anarchists, as you can see from the barons’ wars. 

Whether you agree with Chesterton, it makes an interesting premise, particularly if one accepts his double-meaning of anarchy as not just rebellion against temporal governance, but against natural law.

What if power corrupted, in one's campaign world?  What if personal power and rulership tended to drive people to Chaos?  What if kings with the epithet "the Good" were rare exceptions for a reason?

Tolkien's answer to the question "why do we need adventurers?" in The Hobbit seemed like apathetic or negligent rulers.  But if the typical ruler is wicked, it is even less surprising that the plight of the peasants whose goats are being devoured by gryphons is ignored by the powers that be, and they are left to petition adventurers.  It also explains why in OD&D lords shake down adventurers for magic items, and archmages and high priests geas/quest them for the same.

It provides a great justification for PCs to overthrow existing rulers and take their stuff, while posing new hazards to be navigated.

 

The naturalistic take is that when people acquire power they gain the freedom to indulge their vices and to surround themselves with people who won't stop them.  There is also a Sword of Damocles angle, where rulership is insecure and so rulers tend to grasp at any and all means of holding on to power, including dangerous ones.  Selection effects and the Iron Law of Bureaucracy could play a part as well - those who rise to the top are those who are willing to use all means available to amass power, not those who are honest and just.

The McLeod Company Hierarchy also springs to mind 

To some extent we already see this happening to player characters without codifying it.  PCs have a notorious tendency for wanton disregard for NPC life and property.  Want of money is the root of all evil, and money gives XP, so...  the incentives line up.  We also see it a little as a side effect of the Tampering with Mortality table; gathering XP is dangerous and many PCs have close calls which lead to some spiritual deterioration.  And certainly I have seen PCs rule their domains with secret police and iron fist.

It's funny, that I think this was actually the first I ever heard of Seeing Like a State, and it was about strategy gamers behaving badly.

Mechanically, how might we rig the system such that rulers tend to be bad?  One simple approach is to flip ACKS' random alignment generator, which was on a d6, 1 Chaotic, 2-4 Neutral, 5-6 Lawful.  But maybe for rulers, you do 1-2 Chaotic, 3-5 Neutral, 6 Lawful.

Renegade Crowns' prince generation system tends to produce rather flawed characters.  It is possible to generate one who is a decent person, but rare.  Renegade Crowns' domain engine also turns domains into a source of trouble, hence into temptation to seek additional power to keep a lid on things, maybe without reading the fine print. 

If you like numerical corruption point accumulation systems, you could certainly wire one up so that leveling incurs corruption.  I don't like such systems, personally.

AD&D suggests a less dissociated alternative - for high-level assassins and druids, leveling is a zero-sum game, where you have to go topple the previous Master of Assassins or Arch-Druid in order to level up.  Zero-sum games always bring out the nastiest in people.  A very Damocles situation for the current Master, one in which he is strongly incentivized to accumulate as much power as possible to secure his position, and one in which challengers are likewise encouraged to play dirty.  Imposing similar diegetic requirements at lower levels could be an option.

(What else could we make zero-sum?  Spell acquisition, by removing copying?  Magic swords, by removing crafting entirely?)

Dark Sun and ACKS suggest another angle, with the ability to surpass the limits of human power by abandoning humanity through undeath, apotheosis into a dragon, etc.  If you lower the limits of human potential to, say, 9th level rather than 14th (or even down to 6th), committing crimes against the natural order to surpass human limits becomes much more pressing.

What does a world built with this idea as a premise look like?

Kings and princes are fearsome and dangerous and mostly view people as means, as tools to be used.  Their servants and courtiers and lieutenants may be complicit, or scheming and striving, or just doing what they have to do to get by, or believe that though what they do is repugnant, it is for the greater good.  Down at the bottom, the peasant, the pickpocket, the bartender, and the guard at the gate are basically decent.  They have no power, and so no corruption.  There is honor among thieves, as long as they are little thieves.  But if they get too big, then the knives come out.

Maybe loyalty score modifiers for hirelings based on level could use some changes to match these assumptions. 

But I think this is an important differentiator from grimdark.  In grimdark, even the little people are often basically bad - untrustworthy, cruel, vicious, spiritually ugly.  Needn't be so.

What do gods and churches look like in such a world?  If your high priests are cynical and power-thirsty, are the gods ambivalent about the moral qualities of their priests?  Or are the gods themselves caught in the same traps as high-level characters, perhaps even just ascended mortals?  Do even "good" gods demand great sacrifices of their worshipers to maintain their position against their divine adversaries?  Are they just so alien that they recognize neither natural law nor human morality?  Are they demiurges, tasked to maintain the work of a now-absent creator deity but falling away from their original purpose and natural law over eons of hard decisions and unsatisfiable constraints?

Thursday, April 9, 2026

Guilds and Freedom of the City

Today I stumbled upon wikipedia articles about the livery companies of the City of London and the notion of "Freedom of the City".

It's very fun, almost Pratchettian, that they have a guild for everything.  The Worshipful Company of Makers of Playing Cards?  The Worshipful Company of Human Resource Professionals?  You can't make these up.

I will confess that I have been pretty down on adventurers' guilds.  Does it make sense to have enough wizards in a city to warrant a guild?  Or for thieves to have an officially-sanctioned, chartered liveried company?  Does it make sense to have a single guild for all of the adventurers, despite their divergent interests and the danger to stability that concentrating all that firepower into a single organization has?  Maybe not (then again, maybe the thieves' guild just has a front company).  But it is probably fun, particularly if you have a city government where guilds elect the Lord Mayor and your wizards' guild candidate is running against the haberdashers' guild's candidate (backed by the thieves' guild, perhaps).  There's probably room for an amusing variation on ACKS' senate rules for guilds electing city leadership, if you're into that sort of thing.

The choice between guilds specific to a particular city vs cross-city guilds like the Hanseatic League is also an interesting one.  An inter-city guild provides for players wherever they may happen to be, while a single-city guild without reciprocal privileges elsewhere ties players to a particular place; it creates a home base.

This home basing effect ties somewhat obviously to halls and refuges.  Freedom of the city also ties nicely to some of the ideas from the halls post.  Someone (or a military unit) granted freedom of the city can do things like carrying arms in the city.

There are a number of rights traditionally but apocryphally associated with freemen—the right to drive sheep and cattle over London Bridge; to a silken rope, if hanged; to carry a naked sword in public; or that if the City of London Police finds a freeman drunk and incapable, they will bundle him or her into a taxi and send them home rather than throw them into a cell.  

Obviously a relevant and desirable status for adventurers!  And one which a city council might be careful to grant!  A good motivation for quests - "if we help Edmud the Haberdasher with his missing shipments, maybe we can secure his vote to get freedom of the city."  Basically: citizenship, but of a particular city.

This provides a potential non-mechanical form of progression or campaign progress.  As does progression from freeman to liveryman of a particular guild (with voting rights in city elections).  And then across cities.

This idea of medieval cities with independent governments whose freemen are not tied to feudal lords is also an interesting deviation from ACKS' assumptions about the relation between cities and high-level fighters, where cities are largely subsidiary to a particular domain.  An independent city council and Lord Mayor might come into conflict (open or otherwise) with adjacent feudal domains-holders.

Saturday, February 8, 2025

Against 2d6

The players from my Classic Traveller one-shot last week started asking whether there would be more adventures for those characters.  I felt a certain unease at the prospect, and decided to examine it.

I think I really dislike 2d6 as a core resolution mechanic, and "fighting with" the dice last session reminded me why.

The central tendency is very strong.  You get many results right in the middle of the range, and small modifiers can change the probability of success dramatically when the target number is close to the center of the range.  The total range is also quite small (2-12), so it really doesn't take that many small modifiers stacking up to make success or failure all but certain.  This is the same problem that ACKS 1e ran into with stacking up modifiers to reaction rolls, except that every piece of Traveller is susceptible to this failure-mode.  This was one nice thing about Thousand Suns' move to 2d12 - it becomes much harder for modifiers to completely dominate randomness (apparently I wrote a draft post of a review of Thousand Suns back in 2015 but never published it - oops).

In theory, many Classic Traveller skill rolls have modifiers from attributes and skill level laid out in the text, under the description of the skills.  However, in a time-constrained after-work session, digging out the skill descriptions for every roll is prohibitively time-expensive.  Even in a longer session, it stalls the tempo.  So I am inclined to improvise target numbers.  In an OSR game without a skill system, I would pick probabilities which sound reasonable within the game-world and negotiate with the players.  "That sounds pretty challenging, maybe a 20% chance of success"  "I'm very strong though."  "OK, 35% - give me a 14+ on a d20".  Translating intuitive probabilities of success into 2d6 target numbers is a huge pain, and the central tendency means that there is very little room for fine-grained distinctions between target numbers in the middle of the range.  You go from 72% chance of success on 6+ to 58% chance of success on 7+ to 42% on 8+.  You can only draw fine-grained distinctions out at the edges of the range (11+ vs 12+, for example; 8% vs 3%).  Even there, the granularity of target numbers is no finer than a d20's.

I think the only real virtues of 2d6 systems are that the player-facing math is easy (almost no significant two-digit operations - if your roll plus skill get into two digits, success is a foregone conclusion) and that d6s are easy to come by.  I have heard, apocryphally, that when Gygax first learned of d20s, he went "This changes everything!"  Having returned briefly to pure-d6 gaming, I can see why.

And this all makes me sad, because I have fond memories of Traveller, but man, actually running games on 2d6 kinda sucks.  It's a pity that Traveller d20 was such a poor port (tangentially, I'm shocked that T20 has such good reviews on DriveThru; maybe I should write a dissenting one).

I feel like converting Traveller to just use d20s (and not also importing the rest of the "d20 System"s baggae like T20 did) wouldn't be hard, exactly - just a slog.

Thursday, January 30, 2025

Classic Traveller One-Shot Reflections

I ran a one-shot of Classic Traveller at the office after work last night.  The players crewed a Far Trader carrying a contract cargo across six parsecs, with one intermediate system being a very-low population law level 0 asteroid habitat and the other being a balkanized world with a pirate problem.  This gave us an opportunity to have one ground combat (with the "customs officials" from the asteroid habitat after the players docked to deliver a contract cargo and buy fuel) and one starship combat (with a pirate Far Trader in the balkanized system).

Sadly I did not end up running either combat by Rules-as-Written.  Having ground combat with the "customs officials" inside the starship was more of a Snapshot/Azhanti High Lightning-situation than one where abstract range bands were appropriate, and I ended up falling back to almost a B/X-style "move n squares and then attack or take other non-attack action" turn pattern.  I also used ACKS-style countdown initiative rolled per individual per round.  I did resolve attacks and damage per CT though (or as closely as I understood it).  Having all three of weapon-vs-armor, weapon range, and per-weapon ability-score modifier DM tables was...  a bit much, as a referee trying to abstract all that away from the players.  I did like the lack of adding degree of success to damage rolls like Mongoose 1e does, which meant that calculating the exact degree of success was not important.  Allocating each die of damage to an ability score was also interesting; I ended up in a couple situations going "OK I don't think there's an allocation here where this guy can remain conscious / not-severely-injured".  For the most part it was a "shotguns and SMGs vs cloth armor at close range" combat and characters felt fairly fragile.  The lack of damage reduction from Mongoose-style armor meant that if you took a 4d6 shotgun hit, there was a good chance you were going unconscious.  I could definitely see how higher-damage weapons like from Mercenary could make combat very lethal; if your armor gets penetrated by a 6d6 weapon, you're dead on average.

For the starship combat, there was no way that our conference room table was going to work for full-detail CT Book 2 vector movement with tape measures.  I ended up going with more abstract range-band combat in the Mongoose style.  I messed up pulse laser damage (per the errata, they have -1 to hit and do double damage - so a double-turret pulse laser hit should've been four damage rolls rather than the two I was doing).  Needing Gunner Interact to apply your Gunnery skill is kinda painful, and the Maneuver/Evade programs giving a tiny fraction of Pilot skill as an evasion bonus makes them hard to justify over Auto/Evade.  I do think there's the core of a fun minigame in computer program selection, but having the lack of compute for certain options basically shut down certain character roles felt a bit bad.  Overall I felt like this space combat dragged a bit but maybe it would've been more decisive with errata'd pulse laser damage.  The 9+ target and no attribute DMs for damage control was also rough.  I also mistook the "Hold" result on the damage table for "Hull"; I expected it to say something more like "Cargo".  Maybe my vision is starting to give out.

I'm not sure to what extent switching to Mayday would've helped (or Mayday plus CT's damage table including stuff like Hold).  It looks like Mayday programs are a bit less terrible (like Maneuver/Evade just giving a flat DM).  I think disengaging from combat to a planet's surface might also have been more viable under Mayday than under abstract ranges.

I did end up using the character generation systems from the High Guard, Merchant Prince, Scouts, and Citizens of the Imperium (for a belter) supplements for pregens.  Ultimately I think that I like that the expanded chargen systems from the supplements are more forgiving for survival and enlistment rolls and skills per term, but they still feel low-choice vs Mongoose's three paths per career.  It is still difficult to target certain skills; with one of the characters I was fishing for Medical on Merchant's Prince's Purser->Medic track but got re-assigned to Sales during my first term.  Attributes feel less important in the supplementary character generation systems than in Book 1 chargen; many of the career sub-tracks don't get DMs to survival and promotion throws from attributes, just from having certain skills at certain levels.  I think this might be for the better though; it makes playing 2d6-in-order a lot more viable.

Overall it sounded like the players still had fun.  One player who had never played an RPG before sounded happy.  One player who had played Mongoose Traveller 2e was puzzled at the choice of Classic (which is fair) and complained of a lack of weapon variety (which was more puzzling; seemed to me less of a problem with the system than with my picking a handful of weapons that seemed appropriate for circumstances).  Several were curious about turning it into a campaign, but I worry that I gave them too many opportunities for profit and they will have quite a bit of starting capital if I have to live with the consequences of that.  I guess they have a lot of damage from the starship combat that I would need to figure the costs on, which could soak up a big pile of cash.

I had grand ambitions about giving the party more choices of routes from the starting point to the contract destination, but discarded a couple of worlds as I ran out of time to prep interesting encounters for them and ended up with a minimal, linear path.  I had also thought it would be fun to generate like ten pregens, give the resumes to the Captain, and have him choose which four to hire, but it turns out that generating pregens with the supplementary chargen systems takes a long time and I only ended up making as many as I needed.  I also gave each pregen a secret (generally a side objective with a monetary payout for completion and a couple pieces of equipment in their bags unknown to the rest of the crew) and these were a mixed success.  I had kind of expected players to get out laptops and start communicating in secret, in a Braunstein kind of style, which would have allowed more shenanigans, but they were pretty studiously disconnected from their electronics!  What a problem to have!  I think the very tight weeknight one-shot timeframe precluded the sort of downtime for intrigue that would've made that work better.  Probably I was trying to do too many things at once here; fitting a ground combat *and* a space combat *and* some speculative trading / ship finance management *and* some intra-party intrigue into a three-hour-session in a somewhat-unfamiliar system was a lot.  I should probably consider myself fortunate that it went as well as it did.

Saturday, January 18, 2025

Playing with Classic Traveller Book 1 Chargen

Spent some time this morning generating characters from CT Book 1, intending to use them as pregens for a game in the office.

The inability to follow up a career where you failed to reenlist with another career makes for many more low-term characters than I recall seeing in Mongoose.

I don't think we ever rolled stats in order in Mongoose either.  Given the smaller set of careers, if there's something in particular that the party still "needs", fishing it out is much more challenging.

Intelligence seems, if not "king" of the attributes during character generation, at least very widely applicable.  The only career that doesn't get some sort of benefit for good Int is Army, and Merchants rely almost exclusively on Int.  Navy and Marines both have high thresholds for bonuses, and Marines have the widest set of stats to get bonuses from (ye olde Multiple Ability Score Distribution).

Just under half of the characters I generated died, mostly in their first term after a failed enlistment roll and then drafting into a service where they had no bonuses to survival.

The Other career seems terrible.  If you have the Int for the survival bonus, you also have the Int to go Merchant and pick up rank for extra skill and benefit rolls.  It's funny that the "two skills per term" on the Scout is justified with their lack of promotion, but Other doesn't have ranks or double skills.  I guess the play with Other is to hope for Gambling and the 100k cash roll.  It's on both of their skill tables that aren't Edu gated, and you don't really want to be rolling on Personal Development because the -1 Soc result is worse than nothing.

I was surprised at how hard it has been to fish out Pilot, Engineering, and Computer.  You basically need to be high-Edu Navy, Scout, or Merchant, and neither Scout nor Merchant reward Edu in their career throws.  Leader and Admin are likewise locked behind high Edu.

I had previously been pretty skeptical of the expanded character generation rules from eg Mercenary and High Guard.  They seemed like power creep, but having spent more time with the Book 1 rules, I can definitely see the appeal of the college-type options to guarantee access to certain important skills like Medic and Pilot, as well as access to the Advanced Education skills table.

The aging table also kicks in much more aggressively than in Mongoose; you probably lose 1-2 points of physical attributes after each of terms 4-6, whereas in Mongoose you might get unlucky and lose a couple points after one of those terms but it was inconsistent until you hit 6-7 terms.  In Mongoose after the 4th term you have a 1 in 36 chance of losing 1 point from each physical attribute; in CT that chance of losing 1 point from each physical attribute after your 4th term is like 15%.  In Mongoose after your 4th term your odds of not taking any aging penalties are like 80%; in CT after your 4th term your odds of not taking any aging penalties are closer to 10%.  And no anagathics during chargen like Mongoose.

So between stats in order making enlistment and survival rolls tougher, and harsher aging penalties, I suspect characters probably end up skewing younger under good play.  You're definitely going to pay stats for those terms 4-6 in a way that you probably didn't in Mongoose.  Lack of enlisted ranks combined with shorter careers also makes for fewer rolls for benefits.

I still don't have a workable-looking pregen party with a broad skill distribution, because my dice hate rolling high Edu apparently.  But at least I learned some things.

Saturday, January 11, 2025

Traveller: Knight-Captains

I read Space Viking in December and meant to blog about it but there has been a lot of other reading to blog about lately.  It was very useful context for understanding Traveller's idea of Feudal Technocracy.  The Sword Worlders in Space Viking have planetary kings, continental dukes, and counts of what sound like large industrial conglomerates.  This is obviously somewhat different than what Traveller seems to expect of eg subsector dukes, but it's an interesting idea.

The bottom end of nobility, though, feels a bit underdeveloped in both cases.  If your counts own large corporations, what do your knights own?

Maybe small businesses.  Maybe well-armed small businesses which can be called upon by their lords for military service.  Like far traders with triple turrets, or a mercenary unit.  And really, if you don't have the central authority to keep weapons out of the hands of your people, getting oaths of fealty and to uphold your laws from at least the ones organizing groups of armed men sounds like a reasonable policy from a sovereign's perspective...

There's a certain charm to the idea of "Finished your fourth term in the Navy with a SOC of 12?  You have received word that your eldest uncle passed away, and you are heir to your family's ship.  Arise, Sir Sigismund of the Far Trader Beowulf."  I've heard worse excuses for giving the party a ship.

I don't think that doing this, even in the absence of a starship loan, necessarily removes the financial tension from the game; she's an old, old ship, been in the family for generations, and has lots of quirks and needs lots of maintenance.  The nobility was often in debt historically; you have noblesse oblige to those under you, expenses to keep up appearances and to maintain your status among your peers, and when your lord calls, you must go, even if there may not be profit in the trip.

And then your third cousin shows up to press his claim to the family ship and you have to settle the matter in a gentlemanly fashion, which is to say, dueling.

...  I wonder if there are any good bits to lift from Pendragon or Wolves of God for something like this.

Sunday, January 5, 2025

Classic Traveller: Dark Nebula

 

Continuing my read-through of the Classic Traveller wargames, Dark Nebula was published in 1980 and covers a war between the Solomani and the Aslan over about two subsectors of space, including one difficult-to-traverse nebula.  Turns are two years of in-universe time, each hex is half a parsec, naval units represent individual ships, and ground units are divisions.

Overall the core of this game looks pretty reasonable.  The space combat system is kinda neat.  The defender nominates a ship, the attacker chooses one of their ships to engage it, and then this repeats until one side is out of uncommitted ships, at which point the side with more ships left uncommitted can assign them as they please to the various 1:1 ship combats already committed to.  Once ships are matched up, the resolution of each of these combats looks pretty straightforward.

I think what I like about this fleet combat design is that there are lots of significant choices (what order to nominate and assign your ships in) but little mechanical complexity.  In general this seems like a desirable property in a game.  And at the scale this game is operating at, "where do you assign which assets" probably is the right question to be posing to players.

I'm also tickled by the inclusion of tanker-ships, really mobile refineries that you can park in systems without gas giants to skim hydrogen off of the star and refine it into fuel, allowing that system to be traversed by other ships without delays.  I love me some logistics-infrastructure-construction.

One thing here that I found a bit surprising was that moving ships can move as far as they want on the hex maps as long as they're moving along jump routes between systems with fuel available, until they enter a system that lacks fuel or where there's an enemy presence (or is in the nebula and requires exploration).  It makes some sense under the time-per-turn assumptions and the scale of the map, but "move as far as you want" still made me stop and think.  It almost has a railroad-war feeling, like the American Civil War or World War 1, rather than an open-water naval warfare feeling.  Maybe that's always been true of naval warfare under Traveller's assumptions and I just never realized it.

There are a couple of other surprising things in Dark NebulaIt feels like a somewhat experimental game; there's tech progress from research in the titular nebula, semi-randomized initial boardstate due to the map placement procedure, and neutral forces with reaction rolls, potentially hostile or potentially hireable.  I definitely didn't expect randomization of map layout in a Traveller game set in the Third Imperium continuity.  Some weirdness arises from this - the maps have hex numbers seemingly from a much bigger hexmap, which are very unlikely to end up getting put together into a sensible order during the alternating placement procedure.  I appreciate that the scan quality is good enough to read the hex numbers though!

There are also a couple of other things about the maps which are weird, and not in a great way.  The star density on them is rather lower than is typical for Traveller.  Several of these quarter-subsector maps only have four stars in them, and the densest have eight.  In a typical Traveller subsector, I'd expect more like 40 systems, or 10 per average map on this scale.  I'm not sure how well the balance of unit production against destruction would scale up to higher-density maps and owning more planets.  Also, having a much higher-density graph of systems might lose some of that railroad-war feel and change the character of the game significantly.  Finally, the way Dark Nebula handles ground forces on planets is that there's a box in an empty hex adjacent to each inhabited system, representing the surface of the planet, and you put troop counters there.  But this would not scale well to higher-density maps.  The quality of infrastructure in these inhabited systems is also denoted by the color of the planet's box, which is a bit lousy - printing your own copy of the map requires color, you have to remember what the colors mean, colorblindness problems, etc.  Frankly I found the color-coding confusing on first read and first look at the map; the icons for the stars use random colors not related to the color coding for the system's infrastructure quality.  They're probably supposed to relate to stellar spectrum class but that's not relevant here and we're already gone non-canonical with the random map so...  I don't know why they did that, rather than making the stars the same color as their respective planet boxes.

The lack of compatibility between Dark Nebula's maps and Traveller RPG subsector maps (both in scale and density) also highlights another oddity here - Dark Nebula is the first Traveller wargame I've read that makes no mention of integration with the RPG.  It does seem like integrating a game where turns are two years of in-universe time would be tough, but I was surprised that there was nothing.  I didn't expect much of Invasion: Earth, but we still got one good patron hook there.

What I didn't realize when I initially read Dark Nebula (not until halfway through writing this post and getting kind of suspicious that the combat system seemed much more staid than the rest of the game) was that it was a clear successor to Imperium, published in 1977.  I've only skimmed Imperium, but it looks like it shared the 2-year turn, combat system, turn structure, etc but is played on a fixed map, with slightly more complex fleet compositions including fighters and carriers, and some neat rules about armistices / inter-war periods (allowing the game to be played in a campaign fashion) and interaction between the Imperial player (playing as a frontier governor, not the emperor) and the Third Imperium.  Notably, Imperium does mostly omit tech progress and lacks neutral forces.  Like Dark Nebula, it foregoes any mention of integration with the Traveller RPG (which made more sense in 1977) and still uses the system of planetary surface boxes in adjacent empty hexes.  I may return to Imperium at some point, but given that my interest is at least nominally in RPG integration, I think it may have to wait.

My blind spot for Imperium and trying to understand Dark Nebula's place in the chronology of CT wargames also caused me to take a quick look at 1981's Fifth Frontier War.   This looks like a monster of a game, bringing together the multi-subsector scale of Imperium and Dark Nebula with some details like SDBs and percentage-based damage to units from Invasion: Earth, but with a greater eye towards RPG integration.  First and foremost, hexes in Fifth Frontier War are one parsec rather than Imperium's half-parsec, and turns in Fifth Frontier War are only one week!  But this means that it can't just abstract starship movement into "move as far as you want this turn", so you have to deal with more details.  And fixed maps allowed Fifth Frontier War to put planetary surface boxes around the edges of the board, rather than right next to the systems they're associated with (which, admittedly, might create some difficulty in locating any particular box), allowing it to increase star system density up towards that typical of Traveller RPG campaigns.  Fifth Frontier War looks tremendously ambitious and hideously fiddly, and I can't imagine why it was the last Classic Traveller boxed-set hex and counter wargame.  At the same time I salute the dream of having a metagame world-engine wargame to run concurrently with one's RPG campaign and I look forward to learning its lessons on a more thorough read/post at some point.